Cap for a writing instrument



FIG. 1 is a perspective view showing my new design;

FIG. 2 is a front view of the cap of FIG. 1;

FIG. 3 is a rear view of the cap of FIG. 1;

FIG. 4 is a left side view of the cap of FIG. 1, the right side viewbeing a mirror image thereof; and,

FIG. 5 is a top plan view of the cap of FIG. 1.

The dashed lines are for illustrative purposes only and form no part ofthe claimed design.

The ornamental design for a cap for a writing instrument, as shown anddescribed.